A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron...A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,infrared spectroscopy of adsorbed pyridine,temperature-programmed desorption of ammonia and thermal gravimetric analysis.The structure,acidity and thermal stability of the SO4^2-/TiO2-SnO2 catalyst were studied.Incorporating tin enlarged the specific surface area and decreased crystallite size of the SO4^2-/TiO2 catalyst.The total acid sites of the modified catalyst increased and Bronsted acid strength remarkably increased with increasing tin content.The decomposition temperature of sulfate radical in the modified catalyst was 100 ℃ greater and its mass loss was more than twice that of the SO4^2-/TiO2 catalyst.The SO4^2-/TiO2-SnO2 catalyst was designed to synthesize 1,6-hexanediol diacrylate by esterification of 1,6-hexanediol with crylic acid.The yield of 1,6-hexanediol diacrylate exceeded 87% under the optimal reaction conditions：crylic acid to 1,6-hexanediol molar ratio = 3.5,catalyst loading = 7%,reaction temperature = 130 ℃ and reaction time = 3 h.The modified catalyst exhibited excellent reusability and after 10 cycles the conversion of 1,6-hexanediol was above 81%.展开更多
The gas-phase dehydrogenation of 1,6-hexanediol(1,6-HDO)toε-caprolactone(ε-CL)over the high-performance Cu-based catalysts is highly desirable,but with grand challenges,because the Cu nanoparticles(NPs)are easy to b...The gas-phase dehydrogenation of 1,6-hexanediol(1,6-HDO)toε-caprolactone(ε-CL)over the high-performance Cu-based catalysts is highly desirable,but with grand challenges,because the Cu nanoparticles(NPs)are easy to be sintered with the low Hüttig temperature(<150℃ vs.>250℃ of reaction temperature).Herein,we report a highly efficient silica-encapsulated nano-Cu catalyst(Cu@SiO_(2)/SiO_(2))prepared via a complexation–impregnation method for the dehydrogenation of 1,6-HDO,exhibiting a 1,6-HDO conversion of 95.3%andε-CL selectivity of 80.0%at 270℃.The catalyst also has the outstanding thermal stability(without sintering up to 270℃ for 100 h on stream),which can be attributed to the effective encapsulation of the SiO_(2)shell.In addition,the reaction network of 1,6-HDO dehydrogenation is proved.Finally,the pyridine-diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and in-situ X-ray photoelectron spectroscopy(XPS)reveal that the Cu^(0) species favor the conversion of 1,6-HDO toε-CL.The synergistic effect of Cu+and Cu^(0) benefits the conversion ofε-CL to 2-methylcyclopentanone(2-MCPN).This study is beneficial for designing the high-performance Cu-based catalysts for 1,6-HDO toε-CL,understanding the reaction network of 1,6-HDO dehydrogenation over the Cu-based catalysts,and offering a strong foundation for the largescale production ofε-CL.展开更多
文摘A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,infrared spectroscopy of adsorbed pyridine,temperature-programmed desorption of ammonia and thermal gravimetric analysis.The structure,acidity and thermal stability of the SO4^2-/TiO2-SnO2 catalyst were studied.Incorporating tin enlarged the specific surface area and decreased crystallite size of the SO4^2-/TiO2 catalyst.The total acid sites of the modified catalyst increased and Bronsted acid strength remarkably increased with increasing tin content.The decomposition temperature of sulfate radical in the modified catalyst was 100 ℃ greater and its mass loss was more than twice that of the SO4^2-/TiO2 catalyst.The SO4^2-/TiO2-SnO2 catalyst was designed to synthesize 1,6-hexanediol diacrylate by esterification of 1,6-hexanediol with crylic acid.The yield of 1,6-hexanediol diacrylate exceeded 87% under the optimal reaction conditions：crylic acid to 1,6-hexanediol molar ratio = 3.5,catalyst loading = 7%,reaction temperature = 130 ℃ and reaction time = 3 h.The modified catalyst exhibited excellent reusability and after 10 cycles the conversion of 1,6-hexanediol was above 81%.
基金国家重点研发项目(2022YFA1503200,2021YFC2101901)国家自然科学基金(22122103,21971108,21971111,22271144)+1 种基金中央高校基本科研业务费(020514380304,020514380252 and 020514380272)江苏省研究生科研与实践创新计划项目(KYCX22_0100).
基金the National Natural Science Foundation of China(Nos.22179038,22272053,22072043,21773069,and 21703069)the Special Project for Peak Carbon Dioxide Emissions-Carbon Neutrality(No.21DZ1206700)from the Shanghai Municipal ScienceTechnology Commission,and the Key Basic Research Project(No.18JC1412100)from the Shanghai Municipal Science and Technology Commission.
文摘The gas-phase dehydrogenation of 1,6-hexanediol(1,6-HDO)toε-caprolactone(ε-CL)over the high-performance Cu-based catalysts is highly desirable,but with grand challenges,because the Cu nanoparticles(NPs)are easy to be sintered with the low Hüttig temperature(<150℃ vs.>250℃ of reaction temperature).Herein,we report a highly efficient silica-encapsulated nano-Cu catalyst(Cu@SiO_(2)/SiO_(2))prepared via a complexation–impregnation method for the dehydrogenation of 1,6-HDO,exhibiting a 1,6-HDO conversion of 95.3%andε-CL selectivity of 80.0%at 270℃.The catalyst also has the outstanding thermal stability(without sintering up to 270℃ for 100 h on stream),which can be attributed to the effective encapsulation of the SiO_(2)shell.In addition,the reaction network of 1,6-HDO dehydrogenation is proved.Finally,the pyridine-diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and in-situ X-ray photoelectron spectroscopy(XPS)reveal that the Cu^(0) species favor the conversion of 1,6-HDO toε-CL.The synergistic effect of Cu+and Cu^(0) benefits the conversion ofε-CL to 2-methylcyclopentanone(2-MCPN).This study is beneficial for designing the high-performance Cu-based catalysts for 1,6-HDO toε-CL,understanding the reaction network of 1,6-HDO dehydrogenation over the Cu-based catalysts,and offering a strong foundation for the largescale production ofε-CL.
